High performance switch for microwave MEMS

Abstract

The present disclosure provides for a microelectromechanical switch including a first port (e.g., input port), one or more second ports (e.g., output ports), a cantilever beam, and a mechanical spring connected to the cantilever beam for providing a mechanical force to move the cantilever beam. The cantilever beam extends from a first end, which is in contact with either the first port or one of the second ports, to a second end that is switchably connectable to the other of the first port or said one of the second ports. The first and second ports and cantilever beam may be formed in a coplanar waveguide.

The invention claimed is: 
     
       1. A microelectromechanical switch comprising:
 a first port; 
 one or more second ports; 
 a cantilever beam, having a first end in contact with either the first port or one of the second ports, and extending from the first end toward a second end that is switchably connectable to the other of said first port and said one of the second ports; and 
 a mechanical spring, connected to the cantilever beam, for providing a mechanical force to move the cantilever beam, wherein the mechanical spring is a compression spring. 
 
     
     
       2. The microelectromechanical switch according to  claim 1 , wherein the switch is a lateral switch, and the mechanical spring provides a mechanical force to move the cantilever beam in a lateral direction. 
     
     
       3. The microelectromechanical switch according to  claim 1 , wherein the mechanical spring is configured in a semi-triangular shape. 
     
     
       4. The microelectromechanical switch according to  claim 1 , wherein the mechanical spring provides a mechanical force to move the cantilever beam in an out-of plane direction. 
     
     
       5. The microelectromechanical switch according to  claim 1 , comprising at least three mechanical springs, each mechanical spring connected to the cantilever beam for providing a mechanical force to move the cantilever beam. 
     
     
       6. The microelectromechanical switch according to  claim 1 , wherein the three mechanical springs are arranged in a Y-configuration. 
     
     
       7. The microelectromechanical switch according to  claim 1 , wherein the mechanical spring is actuated by an electrostatic force. 
     
     
       8. The microelectromechanical switch according to  claim 1 , wherein the first and second ports and cantilever beam are formed in a coplanar waveguide. 
     
     
       9. The microelectromechanical switch according to  claim 1 , further comprising an actuator applying a bias voltage, wherein deflection of the cantilever beam is at least in part determined by the applied bias voltage. 
     
     
       10. The microelectromechanical switch according to  claim 9 , wherein the first and second ports and cantilever beam are formed in a coplanar waveguide, and wherein the actuator is connected to a bias line, and wherein the bias line is formed from titanium tungsten and separated from the coplanar waveguide by a layer of silicon dioxide. 
     
     
       11. The microelectromechanical switch according to  claim 1 , wherein either said first port or said at least one second port includes a mechanical stopper for contacting the second end of the cantilever beam, and wherein, when the microelectromechanical switch is open, the second end and the mechanical stopper are at a distance from one another that is greater than a distance between the mechanical spring and ground of a coplanar waveguide in which the first and second ports and the cantilever beam are formed. 
     
     
       12. The microelectromechanical switch according to  claim 1 , wherein the switch exhibits return loss of at least about 22 dB, isolation of at least about 30 dB, and insertion loss of at most about 0.2 dB at one or more frequencies up to about 20 GHz. 
     
     
       13. The microelectromechanical switch according to  claim 1 , wherein the total area of the switch is about 0.09 mm 2 . 
     
     
       14. The microelectromechanical switch according to  claim 1 , comprising at least two second ports, wherein the first end of the cantilever beam is in contact with the first port, and the second end of the cantilever beam is switchably connectable to each of said two second ports, and wherein the cantilever beam is connected to at least two compression springs, each compression spring providing a mechanical force to move the cantilever beam towards or away from a respective one of said two second ports. 
     
     
       15. The microelectromechanical switch according to  claim 14 , wherein the switch exhibits return loss of at least about 25 dB, isolation of at least about 30 dB, and insertion loss of at most about 0.2 dB at one or more frequencies up to about 20 GHz. 
     
     
       16. The microelectromechanical switch according to  claim 1 , comprising at least three second ports and at least three cantilever beams, a first end of each cantilever beam in contact with a corresponding one of the second ports, and a second end of each cantilever beam switchably connectable to a common junction of the first port, and wherein each cantilever beam is connected to a respective mechanical spring, the mechanical spring providing a mechanical force to move the cantilever beam connected thereto towards or away from the common junction of the first port. 
     
     
       17. The microelectromechanical switch according to  claim 16 , wherein the switch exhibits one of:
 return loss of at least about 26 dB, isolation of at least about 30 dB, and insertion loss of at most about 0.22 dB at one or more frequencies up to about 20 GHz for a lateral switch configuration; and 
 return loss of at least about 25 dB, isolation of at least about 22 dB, and insertion loss of at most about 0.35 dB at one or more frequencies up to about 12 GHz for an out-of-plane switch configuration. 
 
     
     
       18. The microelectromechanical switch according to  claim 16 , wherein the total area of the switch is about 0.43 mm 2 . 
     
     
       19. The microelectromechanical switch according to  claim 1 , comprising at least four second ports and at least four cantilever beams, a first end of each cantilever beam in contact with a corresponding one of the second ports, and a second end of each cantilever beam switchably connectable to a common junction of the first port, and wherein each cantilever beam is connected to a respective mechanical spring, the mechanical spring providing a mechanical force to move the cantilever beam connected thereto towards or away from the common junction, wherein the switch exhibits one of:
 return loss of at least about 20 dB, isolation of at least about 30 dB, and insertion loss of at most about 0.26 dB at one or more frequencies up to about 20 GHz for a lateral switch configuration; and 
 return loss of at least about 18 dB, isolation of at least about 20 dB, and insertion loss of at most about 0.43 dB at one or more frequencies up to about 12 GHz for an out-of-plane switch configuration; and 
 a total area of about 0.51 mm 2 . 
 
     
     
       20. The microelectromechanical switch according to  claim 1 , comprising at least six second ports and at least six cantilever beams, a first end of each cantilever beam in contact with a corresponding one of the second ports, and a second end of each cantilever beam switchably connectable to a common junction of the first port, and wherein each cantilever beam is connected to a respective mechanical spring, the mechanical spring providing a mechanical force to move the cantilever beam connected thereto towards or away from the common junction, the switch having at least one of:
 return loss of at least about 18 dB, isolation of at least about 17.5 dB, and insertion loss of at most about 0.78 dB at one or more frequencies up to about 12 GHz for an out-of-plane switch configuration; and 
 a total area of about 0.58 mm 2 . 
 
     
     
       21. The microelectromechanical switch according to  claim 1 , comprising at least seven second ports and at least seven cantilever beams, a first end of each cantilever beam in contact with a corresponding one of the second ports, and a second end of each cantilever beam switchably connectable to a common junction of the first port, and wherein each cantilever beam is connected to a respective mechanical spring, the mechanical spring providing a mechanical force to move the cantilever beam connected thereto towards or away from the common junction, wherein the switch exhibits one of:
 return loss of at least about 19 dB, isolation of at least about 20 dB, and insertion loss of at most about 0.36 dB at one or more frequencies up to about 20 GHz for a lateral switch configuration; 
 return loss of at least about 19 dB, isolation of at least about 17.6 dB, and insertion loss of at most about 0.88 dB at one or more frequencies up to about 12 GHz for an out-of-plane switch configuration; and 
 a total area of the switch is about 0.64 mm 2 . 
 
     
     
       22. The microelectromechanical switch according to  claim 1 , comprising at least eight second ports and at least eight cantilever beams, a first end of each cantilever beam in contact with a corresponding one of the second ports, and a second end of each cantilever beam switchably connectable to a common junction of the first port, and wherein each cantilever beam is connected to a respective mechanical spring, the mechanical spring providing a mechanical force to move the cantilever beam connected thereto towards or away from the common junction, the switch having at least one of:
 return loss of at least about 15 dB, isolation of at least about 17 dB, and insertion loss of at most about 1.0 dB at one or more frequencies up to about 12 GHz for an out-of-plane switch configuration; and 
 a total area of about 0.68 mm 2 . 
 
     
     
       23. The microelectromechanical switch according to  claim 1 , comprising at least ten second ports and at least ten cantilever beams, a first end of each cantilever beam in contact with a corresponding one of the second ports, and a second end of each cantilever beam switchably connectable to a common junction of the first port, and wherein each cantilever beam is connected to a respective mechanical spring, the mechanical spring providing a mechanical force to move the cantilever beam connected thereto towards or away from the common junction, the switch having at least one of:
 return loss of at least about 14.7 dB, isolation of at least about 17 dB, and insertion loss of at most about 1.5 dB at one or more frequencies up to about 12 GHz for an out-of-plane switch configuration; and 
 a total area of about 0.83 mm 2 . 
 
     
     
       24. The microelectromechanical switch according to  claim 1 , comprising at least eleven second ports and at least eleven cantilever beams, a first end of each cantilever beam in contact with a corresponding one of the second ports, and a second end of each cantilever beam switchably connectable to a common junction of the first port, and wherein each cantilever beam is connected to a respective mechanical spring, the mechanical spring providing a mechanical force to move the cantilever beam connected thereto towards or away from the common junction, the switch having at least one of:
 return loss of at most about 15 dB, isolation of at least about 17 dB, and insertion loss of at least about 1.8 dB at one or more frequencies up to about 12 GHz for an out-of-plane switch configuration; and 
 a total area of about 0.92 mm 2 . 
 
     
     
       25. The microelectromechanical switch according to  claim 1 , comprising at least fourteen second ports and at least fourteen cantilever beams, a first end of each cantilever beam in contact with a corresponding one of the second ports, and a second end of each cantilever beam switchably connectable to a common junction of the first port, and wherein each cantilever beam is connected to a respective mechanical spring, the mechanical spring providing a mechanical force to move the cantilever beam connected thereto towards or away from the common junction, the switch having at least one of:
 return loss of at least about 14 dB, isolation of at least about 14 dB, and insertion loss of at most about 2.2 dB at one or more frequencies up to about 12 GHz for an out-of-plane switch configuration; and 
 a total area of about 1.2 mm 2 . 
 
     
     
       26. The microelectromechanical switch according to  claim 1 , comprising at least sixteen second ports and at least sixteen cantilever beams, a first end of each cantilever beam in contact with a corresponding one of the second ports, and a second end of each cantilever beam switchably connectable to a common junction of the first port, and wherein each cantilever beam is connected to a respective mechanical spring, the mechanical spring providing a mechanical force to move the cantilever beam connected thereto towards or away from the common junction, the switch having at least one of:
 return loss of at least about 14 dB, isolation of at least about 14 dB, and insertion loss of at most about 1.9 dB at one or more frequencies up to about 26 GHz for an out-of-plane switch configuration; and 
 a total area of about 2.5 mm 2 . 
 
     
     
       27. The microelectromechanical switch according to  claim 26 , wherein the common junction of the first port comprises a plurality of spokes extending radially therefrom, each spoke switchably connectable to the second end of a respective cantilever beam, wherein the spokes are evenly distributed around the common junction such that each pair of adjacent spokes form a common angle. 
     
     
       28. The microelectromechanical switch according to  claim 1 , wherein the mechanical spring is configured to be compressed in a direction perpendicular to a length of the cantilever beam extending from the first end toward a second end. 
     
     
       29. The microelectromechanical switch according to  claim 1 , wherein the cantilever beam provides the microelectromechanical switch with a degree of freedom in a direction in which the cantilever beam moves, and wherein the mechanical spring provides the microelectromechanical switch with an additional degree of freedom in the direction in which the cantilever beam moves. 
     
     
       30. A switching network comprising:
 a first microelectromechanical switch comprising:
 a first port; 
 one or more second ports; 
 a first cantilever beam, having a first end in contact with either the first port or one of the second ports, and extending from the first end toward a second end that is switchably connectable to the other of said first port and said one of the second ports; and 
 a first mechanical spring, connected to the first cantilever beam, for providing a mechanical force to move the first cantilever beam, wherein the first mechanical spring is a compression spring; and 
 
 a second microelectromechanical switch comprising:
 a third port; 
 one or more fourth ports; 
 a second cantilever beam, having a first end in contact with either the third port or one of the fourth ports, and extending from the first end toward a second end that is switchably connectable to the other of said third port and said one of the fourth ports; and 
 a second mechanical spring, connected to the second cantilever beam, for providing a mechanical force to move the second cantilever beam, wherein the second mechanical spring is a compression spring. 
 
 
     
     
       31. A switching network according to  claim 28 , wherein each of the first microelectromechanical switch comprises at least two second ports, wherein the first end of the first cantilever beam is in contact with the first port, and the second end of the first cantilever beam is switchably connectable to each of said two second ports, and wherein the first cantilever beam is connected to the first compression spring and at least one additional compression spring, each compression spring providing a mechanical force to move the first cantilever beam towards or away from a respective one of said two second ports, and wherein the second microelectromechanical switch comprises at least two fourth ports, wherein the first end of the second cantilever beam is in contact with the third port, and the second end of the second cantilever beam is switchably connectable to each of said two fourth ports, and wherein the second cantilever beam is connected to the second compression spring and at least one additional compression spring, each compression spring providing a mechanical force to move the second cantilever beam towards or away from a respective one of said two fourth ports. 
     
     
       32. The switching network according to  claim 30 , wherein the switching network is configured to operate at a frequency of up to about 20 GHz. 
     
     
       33. The switching network according to  claim 30 , wherein the switching network is configured to operate at a frequency of up to about 26 GHz. 
     
     
       34. A switch comprising:
 a first terminal; 
 a second terminal; 
 a deflectable beam connected to the first terminal, wherein the beam is configured to deflect towards the second terminal, wherein the beam contacts the second terminal when deflected in the direction of the second terminal; 
 a first electrode affixed to the beam; 
 a second electrode spaced apart from the first electrode, wherein a voltage applied to the second electrode causes the first electrode to move towards or away from the second electrode; and 
 a mechanical spring affixed to the first electrode, the mechanical spring having each of a compressed state and an at-rest state, wherein the mechanical spring is in the compressed state when the first electrode moves towards the second electrode, and returns to the at-rest state when the first electrode moves away from the second electrode. 
 
     
     
       35. The switch as recited in  claim 34 , wherein the mechanical spring provides a force to deflect the beam towards the second terminal. 
     
     
       36. The switch as recited in  claim 34 , wherein the mechanical spring provides a force to deflect the beam away from the second terminal. 
     
     
       37. The switch as recited in  claim 34 , wherein the first and second electrodes are spaced farther apart from one another than the first and second terminals are spaced apart.